To find the y-coordinate of the parabola given the quadratic equation \( y = 5x^2 + 8x + 9 \) when \( x = -3 \), we can substitute \(-3\) into the equation:
\[ y = 5(-3)^2 + 8(-3) + 9 \]
Now, we can calculate each term:
- Calculate \( (-3)^2 \): \[ (-3)^2 = 9 \]
- Substitute that into the equation: \[ y = 5(9) + 8(-3) + 9 \]
- Calculate \( 5(9) \): \[ 5 \times 9 = 45 \]
- Calculate \( 8(-3) \): \[ 8 \times -3 = -24 \]
- Combine these results: \[ y = 45 - 24 + 9 \]
- Simplify: \[ y = 21 + 9 = 30 \]
Thus, the y-coordinate of the parabola when \( x = -3 \) is \(\boxed{30}\).